Added unit tests for test RegexViolationErrorMsgFromSecondaryUserStore

[Sachin-Mamoru]

This pull request introduces new test cases and helper methods to improve the validation of usernames in secondary user stores. The most important changes include adding a new test method to verify error messages from secondary user stores, and creating helper methods to mock the necessary components for these tests.

New Test Cases:

• Added testRegexViolationErrorMsgFromSecondaryUserStore method to verify that the correct error message is fetched from the secondary user store when a username violates the regex pattern.

Helper Methods:

• Created setupRealmServiceMocks method to mock the RealmService and associated components.
• Created setupPrimaryUserStoreManager method to mock the primary user store manager and its configurations.
• Created setupSecondaryUserStoreManager method to mock the secondary user store manager and its configurations.
• Created injectMockedRealmService method to inject the mocked RealmService into the IdentityRecoveryServiceDataHolder.
• Created createRequestDTO method to create a UsernameValidationRequestDTO with specified username and realm properties.

Related Issues

• Incorrect Usename Regex Validation Error Message for Secondary Userstore wso2/product-is#21768

Related PRs

• Fix Incorrect Usename Regex Validation Error Message for Secondary Userstore #879

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 50.70%. Comparing base (3dafa8d) to head (74f521e).
Report is 2 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master     #897      +/-   ##
============================================
+ Coverage     50.59%   50.70%   +0.11%     
+ Complexity     2429     2427       -2     
============================================
  Files           298      298              
  Lines         17979    17979              
  Branches       2584     2585       +1     
============================================
+ Hits           9097     9117      +20     
+ Misses         7738     7716      -22     
- Partials       1144     1146       +2     

Flag	Coverage Δ
unit	38.53% <ø> (+0.11%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.